Induction cooking appliances are more efficient, have greater temperature control precision and provide more uniform cooking than other conventional cooking appliances. In conventional cooktop systems, an electric or gas heat source is used to heat cookware in contact with the heat source. This type of cooking is inefficient because only the portion of the cookware in contact with the heat source is directly heated. The rest of the cookware is heated through conduction that causes non-uniform cooking throughout the cookware. Heating through conduction takes an extended period of time to reach a desired temperature.
In contrast, induction cooking systems use electromagnetism which turns cookware of the appropriate material into a heat source. A power supply provides a signal having a frequency to the induction coil. When the coil is activated a magnetic field is produced which induces a current on the bottom surface of the cookware. The induced current on the bottom surface then induces even smaller currents (eddy currents) within the cookware thereby providing heat throughout the cookware.
Due to the efficiency of induction cooking appliances, precise control of a selected cooking temperature is needed. Some systems include a position sensor to determine the position of the cookware in relation to the induction coil to improve efficiency of the induction cooking appliance. Examples of position sensors include capacitance-based position sensors, laser based position sensors, eddy-current sensing position sensors, and linear displacement transducer-based position sensors. However, each of these sensors has disadvantages including impractical size, complexity, and cost.
Thus, a need exists for an improved induction cooktop control method that overcomes the above-mentioned disadvantages. A system and method that can improve cookware position detection would be particularly useful.